PEOPLE has an exclusive behind-the-scenes look at the reunion. Tierney joined the cast of ER in 2000 as nurse Abby Lockhart while La Salle portrayed Dr. Peter Benton. Phifer played Dr. Greg Pratt.

and that stint was a large part of why I was excited when she was cast to replace Camryn Manheim. The latest episode was a much-hyped ER reunion, with Mekhi Phifer joining Tierney in front of the ...

ER may have gone off the air in 2009, but NBC's long-running drama Law & Order is bringing some of the cast members together again. On Jan. 23, the newest episode of the procedural will feature ...